1. Field of the Invention
This invention is related to dual-layer high-solids enamel coating systems containing aluminum-flake pigment which, when applied to a substrate and dried, result in coatings having excellent metallic glamor.
2. Description of the Prior Art
Metallic glamor in the coating art refers to the property of a metallic-pigmented coating that causes the intensity of light reflected from the coated substrate to vary markedly according to the angle from which it is observed. This aesthetic property, which is particularly desired in automotive finishes, is largely the result of a non-random orientation of the metallic flakes in the dried coating, with most of the flakes positioned practically parallel to the coating surface. Heretofore, such orientation has been normally achieved only with low-solids lacquer or enamel coating systems which, although of excellent quality, have relatively high solvent content. Coating compositions in which the solvent content is low, usually 50% by weight of the composition or less, are normally enamel systems. These high-solids enamel systems, however, have been unable to achieve high-quality metallic glamor. The current environmental emphasis on solvent reduction highlights the continued need for a high-solids coating system which provides metallic glamor comparable to that of the lacquer systems.